Digester apparatus



May 2, 1939.

w. H. SHIPMAN 2,156,643

DIGESTER APPARATUS I Filed May 2, 1935 2 Sheets-Sheet l INVENTOR.William H. Shipman ATTORNEY.

May 2, 1939. w. H. SHIPMAN DIGESTER APPARATUS Filed May 2, 1935 2Sheets-Sheet 2 Patented May 2, 1939 I UNITED STATES PATENT OFFICE.

2,156,643 mons'rsa APPARATUS Application May 2, 1935, Serial No. 19,369

14 Claims.

This invention relates to material handling apparatus and it is moreparticularly concerned with chemical apparatus for handling fluids. Itis exemplified herein in connection with a digester A for thepreparation of wood pulp. V

To effectively maintain digester reactions incident to the breakingdown'of wood chips to form pulp, a hot liquor of a pre-determinedchemical constituency is circulated through the digester, in modern highcapacity units. To complete the chemical reactions in the digester in aminimum of time, it is important that effective control of pressure andtemperature be maintained, along with the control of the volume ofliquor circulated. The apparatus for maintaining such control includes afluid pressure relief line and a pressure control connection with theupper part of the -digester. This invention ispartlcularly directed toimprovements in this type of apparatus.

Even when the relief line connections are at the very top of thedigester the relief fluid often carries such a high percentage of solidsthat pumps and other apparatus handling the fluid might quickly berendered inoperative.- To prevent this a screen is provided for therelief line, and it is a desideratum that the screen be located withinthe digester or the digester nozzle. In the present instance, the screenis readily detachable and of such construction that it can be easily 30cleaned. Furthermore, when the screen lsremoved for cleaning a reliefline outlet chamber is entirely exposed so that it may be readilycleaned.. The invention contemplates also a involve the detachment orattachment of the relief line connection with the digester.

The invention also contemplates a digester construction which guides andmaintains a rotary chip distributor and permits that distributor to 40be quickly and accurately positioned within the screen and within thecharging port of the di- The invention contemplates a rotary chipdistributor which imparts a lateral force to the chips and causes suchan arrangement of the chips in the digester that the cooking operationsare enhanced and a better quality of pulp thus assured. It contemplatesa chip distributor having a rotary impeller located below the reliefline screen, and

screen structure, the removal of which does not the digester showing therotary chip distributor as it is used when the digester is beingcharged.

Fig. 2 is a partial perspective view showing the top of the digester,the trolley frame for carrying the chip distributor, and the automaticrelief valve and piping connecting it to the nozzle of the digester. 1

Fig. 3 is a vertical section showing the screen structure and the chipdistributor spider guide on a larger scale.

Fig. 4 is a view looking downwardly from the plane indicated on the line4-4 of Fig. 3.

The digester structure shown in Fig. 1 of the drawings includes ametallic shell l0 supporting a flanged collar I! at the neck of thedigester. Within the collar I2 is a sleeve construction l4 recessed toprovide the space l6 which becomes a part of the relief fluid screenchamber. This sleeve has a flange I8 which rests upon the top of thecollar l2 and maintains the sleeve in operative position.

The lower end of the sleeve l4 extends within the digester to a pointsubstantially beyond the shell II) where its inner end 20 is belied.This promotes anchoring of the lining 22 around the charging port of thedigester.

The drawings also show the sleeve l4 as forming guideways for the arms24 of'a distributor spider. As illustrated, and more particularly shownin Fig. 3 of the drawings, these guideways are provided by ribs 26 and28 integral with the metal of the sleeve.

At the lower end of each 'guideway there is a seat for a distributorspider arm. Each seat is indicated in Fig. 3 as having an inclined face30 corresponding to a similar'inclined surface on eachspider arm. Eachguideway is closed off at its lower end by the material of the sleevewhich forms a shoulder 32. The chip distributing apparatus is therebycorrectly centered and adequately maintained in operative positionwithin the charging port of the digester.

The sleeve 14 is preferably formed so as to correspond with theconfiguration of the collar l2, and it communicates at one side of thedigester with a relief pipe 34 which is shown extending through thecollar l2. This relief pipe in turn communicates with the space I6 whichis closed of! by the sleeve and the screen 36 to form a relief linechamber extendingaround the perimeter of the charging port. The screen3!? preferably rests upon the shoulder 38 at the lower end of therecessed portion of the collar l2, and its inside diameter is preferablyidentical with that of the inside diameter of the lower portion of thesleeve. The screen is preferably formed of metal with upper and loweroutwardly extending flanges 40 and 42 respectively. The lower of theseflanges is shown seated on the shoulder 38 while the upper flange l0closes off the top of the space which forms the relief line screenchamber.

The screen or strainer 36 is provided on itsinner surface with ribsforming upright guideways which are continuations of the guidewaysbetween the ribs 26 and 28 of the sleeve l4. As shown, the upper parts44 and 46 of these ribs are upwardly divergent so as to facilitate theentering and placement of the chip distributor in operative position.Their lower ends 48 and 58 are shown parallel to each other and parallelto the axis of the charging port of the digester.

80 The chip distributor which is, during the distributor element or,impeller, 52 securedto' the lower end of an upright shaft 54 journaledin a bearing 58 preferably integral with the spider arms 24. The upperend of the shaft 54 is connected by means of ,a universal joint 51 andthe telescoping shaft construction 58 to a second universal joint 88.This last universal joint is also connected to the end of an uprightintermediate shaft 82 rotatably mounted in. a journal 6 supported by acarriage 66. The shaft 82 is connected by means of bevel gears 68 and 18with a driving shaft 12 which is shown coaxial with the shaft ll of themotor 18.

The motor 18 may he also connected to a belt and pulley device 18 sothat it may rotate the hopper 88 through the transmission 82 and a belt84 extending around the grooved wheel 86 rigid with the hopper. Thehopper may rotate on rollers 80 which are mounted upon horizontal axesand may be guided by rollers 82 which are rotatable upon vertical axes.

In the operation of the chip distributor the chips are delivered to thehopper 84 in a steady stream and are evenlyv spread by the rotatinghopper 88 before they fall through chute 98 and thence through thecharging port of the digester. As they pass downwardly from the chargingport they are engaged by the impeller 52 and evenly distributed over thedigester so as to avoid undesirable stratifications.

The motor as well as the rotating hopper 88 and all of the superposedmechanism may be carried by a frame I08 which is a part of the carriagemovable along a trackway from one digester to another.' After thedigester is fully charged, the carriage I08 is moved along the track,the telescoping shaft mechanism automatically disconnecting the shaft54. Thereafter the distributor element may be freely elevated from itsillustrated position, the chute 98 removed, and the cover I04 for thedigester placed in position so that the cooking operation can begin.

Fig. 2 shows the relief pipe 34 connected to the automatic relief valveI88 at one end and to a digester coupling at the other end. Thiscoupling includes a flanged and threaded nipple I08 telescoped within anexterior nipple II. A coupling ring I I2 presses the gasket Ill againstthe latter nipple to tightly maintain the assembled parts in theiroperative positions.

Whereas the invention has been described with reference to theparticular apparatus shown in the drawings it is not limited to all thelimits thereof, but is of a scope commensurate with the sub-joinedclaims.

What isclaimed is:

1. Apparatus of the class described comprising, in combination, adigester, a material distributor temporarily insertible through acharging opening in the top of the digester, a structure framing theopening and formed to provide seats for the distributor, means on saidstructure forming guides leading to said seats, and an annular strainerhaving guideways formed thereon as continuations of the above mentionedguides.

24 In combination, a digester having arecessed nozzle, a chipdistributor, a relief line strainer .ring'seated within the nozzlerecess, and means on said ring for guiding the distributor into itsoperative position.

3. In combination, a digester having a recessed charging nozzle, achannel-shaped screen seated within the recess and cooperating with thewalls thereof to form a relief fluid chamber, a relief line extendingthrough the side of the nozzle and communicating with the chamber, achip distributor adapted to be temporarily seated and operated withinthe nozzle, a spider extending across the nozzle and supporting thedistributor, aligned guideways formed by parts on the nozzle and thescreen for guiding the ends of the spider into operative position. andstops formed in the nozzle at the lower ends of the guideways.

4. In a digester, an exterior metal casing formed with a chargingopening at the top, a nozzle defining the opening, a flanged sleeveconstruction extending through the frame and the opening to a positionwithin the casing with the flange of the sleeve resting'upon the top ofthe nozzle so that the sleeve is thereby supported in its operativeposition, a digester fluid relief line extending through the side of thenozzle and communicating with a recess formed in the upper part of thesleeve, a digester lining closely fitting around the inner ends of thesleeve and secured to the casing, and an easily detachable metallicstrainer ring disposed within the recess and combining with the wallsthereof-to form a relief fluid chamber communicating with the reliefline.

5. In combination, a digester having a charging nozzle at'the topthereof, a recessed and flanged from the top of the digester, a metallicstrainer ring cooperating with an annular recess in the collar forforming an annular fluid relief chamber, a distributor spider, andguideways formed on the collar and the strainer for guiding the spiderinto its operative position.

'7. Apparatus of the class described comprising, in combination, adigester, a material distributor insertible temporarily through thedigester nozzle, a structure framing the opening and formed to provideseats for the distributor, said structure forming guideways leading tosaid seats and an annular strainer having guideways formed thereon ascontinuations of the above mentioned guides, means for discharging astream of chips through the nozzle so that they contact with thedistributor, and means for rotating the distributor.

8. In combination, a digester formed with a recessed nozzle, a chipdistributor, a relief line strainer ring seated within the nozzlerecess, and aligned means on said ring and the nozzle for guiding thedistributor into its operative position.

9. In combination, a digester having a metallic shell, an acid prooflining within the shell, a flanged collar extending through a nozzle atthe top of the digester and having a lining contacting flange at itsinner end, the collar being supported from the top of the digester, ametallic strainer ring cooperating with an annular recess in the collarfor forming an annular fluid relief chamber, a distributor spider, andaligning ribs formed on the collar and the strainer for guiding thespider into its operative position.

10. In combination, a digester formed with a charging opening the wallsof which present an annular recess, a distributor, distributor supports,a readily detachable sheet metal strainer ring seated within the recessand forming with the walls thereof an annular relief line chamber, andmeans on said ring for guiding the distributor toward its operativeposition on said supports.

11. In combination, a digester formed with an opening which is boundedby a recessed frame, a channel shaped strainer seated within the recessand cooperating with the walls thereof to form a fluid chamber, a reliefline extending through the frame and communicating with the chamber, a

material distributor adapted to be temporarily seated and operatedwithin the opening, a distributor support extending across the opening,aligned guideways formed by parts of the frame and the screen forguiding the ends of thesupport into operative position, and seats formedin the frame at the ends of the guideways.

12. In combination, a digester having a recessed charging nozzle, ascreen seated within the recess and cooperating with the walls thereofto form a relief fluid chamber, a relief line extend-. ing through theside of the nozzle and communicating with the chamber, a rotatable chipdistributor adapted to be, temporarily seated and operated within thenozzle, a distributor support extending across the opening, alignedguideways formed by parts on the nozzle and the screen for guiding theends of the spider into operative position, and stops formed in theframe at the lower ends of the guideways.

13. In a digester, an exterior metal casing formed'with a chargingopening at the top, a nozzle defining the opening, a flanged sleeveconstruction extending through the frame and the opening to a positionwithin the casing with the flange of the sleeve resting upon the top ofthe nozzle so that the sleeve is thereby supported in its operativeposition, a digester fluid relief line extending through the side of thenozzle and communicating with a recess formed in the upper 2 part of thesleeve, a digester lining closely fitting around the inner ends of thesleeve and secured to the casing, and an easily detachable strainer ringclosing the recess and combining with-the walls thereof to form a relieffluid chamber communicating with the relief line.

14. In combination, a digester having a charging nozzle at the topthereof, a recessed metallic sleeve extending into the opening, and anannular strainer which is channel shaped in cross section so that itwill cooperate with the sides of the recess walls to form a fluidchamber for the digester relief line.

WILLIAM H. SHIPMAN.

